The purpose of the Child and Adolescent Trial for Cardiovascular Health (CATCH) is to determine the effects of a three-year program of school- and family-based interventions on children's risk for cardiovascular disease. At each of four national sites (California, Louisiana, Minnesota, and Texas), the CATCH project will recruit one cohort of 3rd grade students in 1991-92 in 24 schools and randomize schools, after baseline assessment, to one of three conditions: 1) school-based interventions, 2) school- plus family-based interventions, and 3) control. The school-based interventions include three consecutive years of classroom curricula, as well as changes in the school food service, physical education program, and school-wide smoking policies. The familybased interventions include home activity programs and family nights. The primary outcome of interest is cholesterol change; secondary outcomes include blood pressure, dietary intake of calories, fat, and sodium, minutes of moderate to vigorous physical activity, and intentions not to use tobacco. It is hypothesized that at post-test, students exposed to the program of interventions, after controlling for baseline values, will have lower cholesterol, lower intake of dietary fat and sodium, increased physical activity, and less intentions to smoke than the control group. It is further hypothesized that the students exposed to the family-based interventions will have more desireable dietary patterns than students exposed to the school-based interventions alone.